Project Summary This core will provide a seamless translational infrastructure to support the research on CLL tissues planned in this application. This will include the provision of fresh or frozen primary CLL samples (peripheral blood, bone marrow and lymph node) for all in vitro experiments, with full clinical annotation and follow-up, from among the over 1200 patients already enrolled in the DFCI CLL tissue bank as well as newly enrolled patients. The core includes extensive serial sampling from many CLL patients treated with novel agents, and will focus particularly on the acquisition of progression and relapsed samples during this grant period. This core also includes an effort to develop the capability of using primary CLL cells to generate in vivo primagraft models. These models are a significant and increasingly appreciated tool for the analysis of newly identified genetic lesions, associated signaling and survival pathways, rational therapeutic targets and mechanisms of drug resistance. CLL cells or isogenic cell lines will be delivered by tail vein injection or directly implanted within the coated scaffolds. CLL cells delivered to the scaffolds are expected to engraft within this ?humanized mouse? system which is meant to simulate vital human-human heterotypic interactions between CLL and BM cells. These primagraft models could then be used to characterize biology and assess response to therapy of the CLLs. This core ultimately also readily provides the opportunity for translation to clinical research trials in humans, as our clinical DFCI CLL program consists of recognized leaders in managing all phases of clinical research trials as well as multicenter studies.